Final answer:
Bioavailability is the term that measures drug absorption and the total amount of drug in the blood. It is influenced by factors such as drug formulation and route of administration. Calculating the area under the drug concentration-time curve (AUC) can determine bioavailability.
Step-by-step explanation:
The term that measures drug absorption and the total amount of drug in the blood is bioavailability. Bioavailability is the fraction of a drug that reaches systemic circulation after administration and is available to produce its pharmacological effects. It is influenced by factors such as drug formulation, route of administration, and first-pass metabolism.
For example, when a drug is administered orally, it has to pass through the gastrointestinal tract and undergo metabolism in the liver before it reaches the systemic circulation. The bioavailability of an oral drug can be affected by factors such as gastric emptying time, drug solubility, and drug interactions. On the other hand, intravenous administration bypasses the gastrointestinal tract and liver, resulting in higher bioavailability.
One way to measure bioavailability is by calculating the area under the drug concentration-time curve (AUC), which represents the total amount of drug in the blood over time.